It is intended to investigate the physiological basis of the increase in glomerular filtration rate (GFR) which occurs during the normal pregnancy with particular reference to the role of some hormones including prolactin. Also, since normal pregnancy is associated with increases in the circulating level of a number of vasoactive hormones, a series of studies will investigate the importance of these hormones in the control and maintenance of GFR. Further, since renal disease and hypertension are major complication of pregnancy, the effects of pregnancy will be investigated on a) several experimentally-induced models of antecedent renal disease; b) pre-existing, experimentally-induced hypertension; c) diabetes: the role of the thromboxane (TX) system in the diabetic and normal kidney will also be investigated and d) experiments will be conducted to determine whether a defect in prostaglandin (PG) biosynthesis plays a casual role in the pathogenesis of pre-eclampsia. The technique of "in-vivo" micropuncture will be employed in the euvolemic Munich-Wistar rat in order to permit a complete evaluation of glomerual hemodynamics in normal and complicated pregnancies and these data will be compared to virgin controls. It is anticipated that these experiments will yield insight into both the physiological control of the glomerular hemodynamic response to normal pregnancy and the pathogenesis of pregnancies which are complicated by hypertension and/or kidney disease.